1. Field of the Invention
The present invention relates to a medium recording a color transformation lookup table, a printing apparatus, a printing method, a medium recording a printing program, and a medium recording a color transformation program.
2. Description of the Prior Art
Image processing devices such as displays and printers have their inherent color gamut; that is, the range of colors producible by the device. Different image processing devices usually have different volumes of color gamut. When handling even the same image, the color gamut of one image processing device is compressed to fall within the color gamut of the other image processing device, thereby the color image is expressed in the color gamut of the image output device. In common techniques for such compression, chroma contraction toward the lightness axis takes place in a Lab space, not actively causing hue change.
In color transformation according to the foregoing techniques, problems were posed which will be described blow.
If there is considerable difference in volume between the color gamut of one image processing device and the color gamut of the other image processing device, high-rate compression occurs and changes chroma to a great degree, resulting in color unbalancing. Due to the chroma change in certain hues, viewers might sense colors different from the inherent colors by color contrast. For example, the color gamut of an ink-jet printer using a CMYK ink set is characterized by quite lower chroma in the color region of the red hue to the green hue and in the low lightness range. If an image of the leaves of a plant including shadows presented on a display is printed with such printer, the dark green shadows cannot gain sufficient chroma and look dark brown by contrast with green in the surroundings.